//https://api.dartlang.org/stable/2.2.0/dart-core/List-class.html

//list继承了Iterable
main(){
  print('abc');
  Duration drt = new Duration(seconds:10);//设置一个10秒的延迟
  Future.delayed(drt,(){
  print('edf');//延迟执行的程序
  });
}